KR20060039073A - Apparatus and method for decoding error correction code of high density optical disc - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for decoding error correction codes of high density optical discs. When demodulating to a format and performing error correction (ECC) and decoding, a part of the LDC codeword is searched and referred to along with a BIS codeword to indicate whether a burst error has occurred. By more precisely declaring (Erasure), two adjacent bursts may exist with the burst error present in the middle of the BC codeword from the next non-IS codeword, or with no burst error present in the Even if an error occurs in a non-IS codeword, an erasure declaration that correctly indicates a burst error occurs This is a very useful invention that can effectively prevent the occurrence of errors in error correction and decoding operations according to the erasure declaration.

Blu-ray Disc, Recording Frame, BIS, LC, Burst Error, Eraser, Error Correction Code, Decoding

Description

Apparatus and method for decoding error correction code of high density optical disc}             

FIG. 1 illustrates a configuration of a recording frame of a general high density optical disc.

FIG. 2 illustrates an embodiment in which an erasure is declared in a general LC codeword.

3 and 4 illustrate an embodiment in which an eraser is incorrectly declared in a general LC codeword.

5 shows a configuration of an error correction code decoding apparatus of a high density optical disc according to the present invention;

6 illustrates an embodiment in which an erasure is declared in an LD codeword according to the present invention;

FIG. 7 illustrates byte positions after 17PP demodulation search-referenced in an erasure declaration unit according to the present invention;

8 illustrates a 17PP modulation bit conversion rule searched for in an erasure declaration unit according to the present invention.                 

9 and 10 illustrate an embodiment in which an erasure is normally declared in an LCD codeword according to the present invention.

※ Explanation of code for main part of drawing

10 demodulation section 11 BIS decoding section

12: LDC decoding unit 13: erasure declaration unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for decoding an error correction code for a high density optical disc. The present invention relates to an error correction method more accurately for a data stream read from a high density optical disc such as a Blu-ray Disc (BD). And an error correction code decoding apparatus and method for a high-density optical disc for enabling decoding.

In general, a high-density optical disc, such as a Blu-ray disc BD, capable of recording or playing back high-definition video data and high-quality audio data for a long time, as shown in FIG. 1, has 1288 data bits. Recording Frames are recorded, one recording frame comprising four 38-byte Log Distance (LDC) codewords and one 1-byte Burst Indicator Subcode (BIS) codeword, It consists of 20-bit frame sync and 28 1-bit DC-controls.

In the meantime, the LDC codeword and the BIS codeword use different Reed-Solomon codeword schemes, and the LC codeword is RS (248,216,33). The codeword method is used, and the RS codeword method is used for the non-IS codeword.                         

The LDC codeword and the BIS codeword may be, for example, stored in an optical disc device such as a Blu-ray Disc recorder or a Blu-ray Disc player. When decoding the recorded recording frame, it is used as a codeword for performing an error correction operation.

On the other hand, in the optical disc device such as the Blu-ray Disc recorder or Blu-ray Disc player, as shown in FIG. 2, the next 1 byte of non-IS is in the state where an error occurs in 20-bit frame sync. (BIS) When an error occurs in a codeword or when two or more adjacent BAIS codewords occur in succession, a burst error occurs in the 38 byte LDC codeword existing between them. In other words, it is determined that an error has occurred continuously due to a scratch or the like due to a scratch, such as 40 bytes, and declares an erasure.

In addition, the error correction (ECC) operation is performed more precisely on the LC codeword in which the eraser is declared as described above, and the normal error correction is performed on the remaining other LC codewords. By performing the operation, error correction and decoding operations can be performed more efficiently.

However, in the general optical disk device, as described above, when an error occurs in frame synchronization and a non-IS codeword of the next 1 byte, or an error occurs continuously in two adjacent non-IS codewords, Since the eraser is declared in the LC codeword present in the, as shown in FIG. 3, a burst error of less than 40 bytes in length is the next non-IS codeword from the middle of the LC codeword. If present, the error that causes the burst error to not declare the eraser for the LC codeword is present will occur.

In addition, as shown in FIG. 4, even when a burst error does not exist in the LD codeword, when an error occurs in two adjacent non-IS codewords, an eraser is declared in the existing DC codewords. As a result, error correction and decoding operations are abnormally performed.

Accordingly, the present invention was created to solve the above problems, and for example, a predetermined format such as a 17PP demodulation scheme, which is a data stream read from a high-density optical disc such as a Blu-ray disc (BD), is set in advance. In the case of demodulation, error correction (ECC) and decoding, a part of an LDC codeword is searched and referred to along with a BIS codeword to indicate that a burst error has occurred. It is an object of the present invention to provide an error correction code decoding apparatus and method for a high-density optical disc for more precisely declaring Erasure so that error correction and decoding operations according to an erasure declaration can be normally performed.

The error correction code decoding method of the high density optical disc according to the present invention for achieving the above object, demodulates the data stream read from the high density optical disc in a predetermined format, the BIS codeword and the LC (1) dividing and outputting (LDC) codewords; Deciding whether or not a burst error has occurred after decoding the BCS codeword by searching the decoded BCS codeword and some bytes of the demodulated DC codeword; And three steps of variably performing an error correction and decoding operation on the LC codeword according to whether the burst error has been declared.

In addition, the error correction code decoding apparatus of the high density optical disc according to the present invention demodulates a data stream read from the high density optical disc into a predetermined format, and converts the data stream into a BIS codeword and an LDC codeword. Demodulation means for separate output; Non-IS decoding means for decoding the non-IS codeword outputted separately; Erasure declaration means for declaring an erasure indicating whether a burst error has occurred by searching and referring to the decoded BIS codeword and some bytes of the demodulated LED codeword; And an LCD decoding means for variably performing an error correction and decoding operation on the LED codeword depending on whether the eraser is declared.

Hereinafter, a preferred embodiment of an error correction code decoding apparatus of a high density optical disc according to the present invention will be described in detail with reference to the accompanying drawings.

First, the error correction code decoding apparatus and method of the high-density optical disk according to the present invention can be applied to an optical disk device such as a Blu-ray Disc recorder or a Blu-ray Disc player. As shown in FIG. 5, the decoding device may include a demodulator 10, a BIS decoding unit 11, an LDC decoding unit 12, an erasure declaration unit 13, and the like.

On the other hand, the demodulator 10 demodulates the data stream read out from the optical disc in a predetermined format, for example, 17PP demodulation, into BIS codewords and LDC codewords, respectively. The BIS decoding unit 11 decodes the BIS codeword output from the demodulation unit 10 using a decoding scheme corresponding to the RS (62, 30, 33) codeword scheme. .

In addition, the LDC decoding unit 12 decodes the LCD codeword output from the demodulator 10 by a decoding method corresponding to the RS (246, 216, 33) codeword method. With reference to the eraser selectively declared in the laser declaration unit 13, fine error correction and decoding operations are performed on the LC codeword in which the eraser is declared, and the eraser is not declared. Normal error correction and decoding operations are performed on the C codeword.

In addition, the erasure declaration unit 13 searches for and confirms whether an error exists in the non-IS codeword output from the BIS decoding unit 11, and also outputs the LCD code output from the demodulation unit 10. For example, as shown in FIG. 6, the 19th, 20th, 58th, 59th, 97th, 98th, 136th, and 137th bytes of the LC codeword outputted from the demodulator 10 are checked. It checks and checks whether there is an error in the byte.

On the other hand, when an error exists in the corresponding byte and an error occurs in the non-IS codeword before or after the check result, the erasure declaration unit 13, in the corresponding section, burst error (Burst Error) Declaring an erasure indicating that the occurrence of the symbol, as shown in Fig. 7, the 19th byte position after the 17PP demodulation process corresponds to the 221 to 233th bit position before the 17PP demodulation, As described above, when the 221 th to 233 th bit values violate a preset 17PP modulation bit conversion rule, it is determined that an error has occurred at the corresponding 19 th byte position.

In addition, since the 20 th byte position which has undergone the 17PP demodulation process corresponds to the 233 th to 245 th bit positions before the 17 PP demodulation process, as shown in FIG. 8, the 17 th modulation bit is set in advance as the 233 th to 245 th bit values. If the conversion rule is violated, a series of operations are performed to determine that an error has occurred at the corresponding 20th byte position.

Accordingly, as shown in FIG. 6, when an error exists at the 19th or 20th byte position of the LC codeword and an error occurs in the next non-IS codeword, a burst error occurs in the corresponding section. It determines that it exists, and declares an erasure.

On the other hand, even when an error occurs before and after the non-IS codeword, respectively, when there is no error at the 58th or 59th byte position of the LC codeword, the burst occurs for the LC codeword existing therebetween. The error is determined not to exist, and the eraser is not declared.

If an error occurs in the 97th or 98th byte position of the LC codeword and an error occurs in the previous and subsequent non-IS codewords, respectively, the burst occurs for the LC codeword existing therebetween. It determines that an error exists and declares an erasure.

In addition, when an error occurs in a previous non-IS codeword in a state where an error does not exist at the 136th or 137th byte position of the LC codeword, it is determined that a burst error does not exist for the corresponding PC codeword. Thus, the erasure is not declared.

That is, as shown in Fig. 9, for example, when a 20-byte-long burst error is present in the next non-IS codeword from the middle of the LC codeword, the LC codeword in which the burst error exists is present. If an error occurs in two adjacent non-IS codewords as shown in FIG. 10, a burst error does not exist in the LC codeword. Since the eraser is not declared in the LC codeword, the LDC decoding unit 12 may normally perform error correction and decoding operations according to the eraser declaration.

Or more, preferred embodiments of the present invention described above, which is posted for the purpose of illustration, those skilled in the art to improve the various other embodiments within the spirit and technical scope of the present invention disclosed in the appended claims below Changes, substitutions or additions will be possible.

The apparatus and method for error correction code decoding of a high density optical disc according to the present invention constructed and constructed as described above, for example, pre-set 17PP demodulation of a data stream read from a high density optical disc such as a Blu-ray disc (BD). When demodulating to a predetermined format such as a scheme, and performing error correction (ECC) and decoding, a burst error occurs by searching for a part of an LDC codeword together with a BIS codeword. By more precisely declaring an erasure indicating that the burst error is present in the next non-IS codeword from the middle of the LC codeword, or with no burst error in the LC codeword, Eraser indicating that a burst error occurs even when an error occurs in two adjacent non-IS codewords. It is a very useful invention to be able to accurately declare and declare a declaration, and to effectively prevent an error from occurring in error correction and decoding operations according to an erasure declaration.

Claims (12)

Demodulating the data stream read out from the high-density optical disc into a predetermined format, and outputting the data stream separately into a BIS codeword and an LDC codeword; Deciding whether or not a burst error has occurred after decoding the BCS codeword by searching the decoded BCS codeword and some bytes of the demodulated DC codeword; And And an error correction and decoding operation for the LC codeword variably according to whether or not the declared burst error occurs. The method of claim 1, In the first step, a data stream read from a Blu-ray Disc is demodulated by a 17PP demodulation method, and separately outputted as a BIS codeword and an LDC codeword. An error correction code decoding method for a high density optical disc, characterized in that. The method of claim 1, In the step 2, after decoding the BCS codeword, the error occurrence of the decoded BAS codeword and the occurrence of an error of some bytes of the demodulated PC codeword are searched and referred to. An error correction code decoding method for a high density optical disc, characterized by declaring an erasure indicating the occurrence of a burst error when errors occur continuously. The method of claim 3, wherein Some bytes of the LC codeword are one or more bytes among 19, 20, 58, 59, 97, 98, 136, and 137th bytes in the LC codeword demodulated by the 17PP demodulation scheme. Decoding method. The method of claim 4, wherein And determining that an error has occurred at a corresponding byte position when any one of the bytes violates a preset 17PP modulation bit conversion rule. The method of claim 1, In step 3, a precision error correction operation is performed on a portion where the burst error occurrence is declared, and a general error correction operation is performed on a portion where the burst error occurrence is not declared. Correction code decoding method. Demodulation means for demodulating the data stream read out from the high-density optical disc into a predetermined format, which is separately output as a BIS codeword and an LDC codeword; Non-IS decoding means for decoding the non-IS codeword outputted separately; Erasure declaration means for declaring an erasure indicating whether a burst error has occurred by searching and referring to the decoded BIS codeword and some bytes of the demodulated LED codeword; And And an LCD decoding means for variably performing an error correction and decoding operation on the LCD codeword according to whether or not the eraser is declared. The method of claim 7, wherein The demodulation means demodulates the data stream read from the Blu-ray Disc by 17PP demodulation, and outputs the BIS codeword and the LDC codeword separately. An error correction code decoding apparatus for a high density optical disc, characterized in that. The method of claim 7, wherein The erasure declaration means searches for an error occurrence of the decoded BSS codeword and an error occurrence of some bytes of the demodulated DC codeword, and when an error occurs more than 20 bytes in length, a burst error. An error correction code decoding apparatus for a high density optical disc, characterized by declaring an erasure indicating an occurrence. The method of claim 9, Some bytes of the LC codeword are one or more bytes among 19, 20, 58, 59, 97, 98, 136, and 137th bytes in the LC codeword demodulated by the 17PP demodulation scheme. Decoding device. The method of claim 10, And determining that an error has occurred at a corresponding byte position when the one byte violates a preset 17PP modulation bit conversion rule. The method of claim 7, wherein The decoding means for decoding the error correction code of the high density optical disc, characterized in that for performing the precision error correction operation on the portion where the eraser is declared, and the general error correction operation for the portion where the eraser is not declared. Device.

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